Hi there, a client has been getting this error on the site that I have designed when he tries to add a link to the menu. I have added a screenshot to show what error shows up. Do you guys have any idea on how to fix this? Do I just need to remove the plugin that is seemingly seeming to be causing this (W3 Totalcache)? Thanks a lot for your help in advance,
Ps. I hope the screenshot is readable, if not, please tell me, so I can make another one for my client.